Prior art pressure regulators have provided stable pressure outputs of operating fluids used in pneumatic and hydraulic fluid systems. Prior art pressure regulators typically include an input port and an output pressure region. A valve member is exposed to the output pressure and is connected to a biasing member. The pressure within the output pressure region acts on the valve member to counteract the force of the biasing means and move the valve member in response to changes in the pressure of the output pressure region. When the force of the output pressure acting on the valve member exceeds the force of the biasing means which acts upon the valve member, the valve member will be pressed against a valve seat to seal against fluid flow through the pressure regulator. When the force of the output pressure acting upon the valve member is less than that of the force of the biasing means, the valve member will move away from the valve seat and fluids may then again flow through the pressure regulator.
Typically, the biasing means is provided by a spring. The set point of a pressure regulator is selected by compressing the spring with a control means such that the space between one end of the pressure regulator and the control means is reduced in order to increase the compression of the biasing member, which presses the spring against the valve member with a force that determines the output pressure. If an increase in the output pressure is desired, typically the biasing means is further compressed to cause the biasing means to push against the valve member with a greater force. As increases in pressures are desired, more force must be exerted to compress the biasing means in order to cause the biasing means to press harder against one end of the valve member. A desired pressure output of the pressure regulator is selected by selecting a distance between the valve seat and the control means.